JPS5931119Y2 - electrostatic transducer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an electrostatic transducer, and particularly to one that effectively improves its efficiency.

As is well known, an electrostatic transducer used as an electro-acoustic system conversion device such as a speaker in audio equipment is made up of a fixed electrode and a vibrating membrane (movable electrode) that are placed opposite each other with a predetermined gap. Although the characteristics are quite good, the problem is that the conversion efficiency is low.

By the way, in order to most effectively improve the conversion efficiency, the gap between the vibrating membrane (movable electrode) and the fixed electrode should be made as narrow as possible.

However, simply narrowing the gap tends to cause an undesirable situation in which the vibrating membrane comes into contact with the fixed electrode, making it unsuitable for high output applications.

Therefore, this idea was made in view of the above points, and it is possible to prevent an undesirable situation where the diaphragm comes into direct contact with the fixed electrode even if the gap is narrowed. It is an object of the present invention to provide an extremely good electrostatic transducer that can effectively improve conversion efficiency.

In other words, the electrostatic transducer according to this invention is
By providing convex portions formed in a predetermined pattern using an insulator on the surface of the diaphragm that faces the fixed electrode with a predetermined gap, the diaphragm will remain stable even if the amplitude of the diaphragm is limited and the gap is narrowed. It is characterized in that it can prevent direct contact with the fixed electrode.

An embodiment of this invention will be described in detail below with reference to the drawings.

That is, in FIG. 1, 11 indicates a large number of communicating holes H1, H.
2, which is a fixed electrode having a vibrating membrane (movable electrode) 1 via a spacer 12 interposed on the negative end of the fixed electrode.
3 is provided in opposition.

In this case, the vibrating membrane (movable electrode) 13 is stretched over the ring-shaped support member 14 on the lower side in the case shown in the figure, but it is preliminarily attached to at least the surface facing the fixed electrode 11 (or both surfaces are possible). Convex portions 131, 132, . . . formed of an insulating material in a predetermined pattern, such as concentric circles, are provided on the top.

Note that the gap between the fixed electrode 11 and the vibrating membrane (movable electrode) 13 is substantially determined by the spacer 12, but at least it is determined by the convex portion provided on the vibrating membrane (movable electrode) surface. 131°, 132..., and set as narrow as possible according to the desired output. In the above configuration, the fixed electrode 11 and the vibrating membrane An input signal is applied from a signal source (not shown) to the movable electrode (13) via a bias power source E such as a battery and a drive circuit 14 such as a transformer.

As a result, the vibrating membrane (movable electrode) 13 is vibrated in a direction in which it is attracted to or repelled from the fixed electrode 11 depending on the signal intensity.

The resulting air vibrations are nothing but the input signal converted into sound.

By the way, in the above operation, the amplitude of the vibrating membrane (movable electrode) 13 is the same as that of the fixed electrode 1 of the vibrating membrane (movable electrode) 13.
The vibrating membrane (movable electrode) 13 on the surface of the fixed electrode 11 is limited by the presence of a predetermined pattern of protrusions 131, 132 made of an insulator provided on the side facing the fixed electrode 11.
Therefore, even if the gap is narrowed in order to improve conversion efficiency, undesirable situations caused by contact can be reliably avoided.

Moreover, this contact prevention function is similarly ensured even when static suction force is applied during assembly.

FIG. 2 shows another embodiment. In this case, in order to eliminate the need for a bias power source, an electret 111 charged to a predetermined polarity is attached to a back electrode 112 as the fixed electrode 11. Other than that, it is the same as the previous case.

It goes without saying that this invention is not limited to the embodiments described above and illustrated, but can be modified and applied in various ways without departing from the gist of the invention.

Therefore, as detailed above, according to this invention, by providing convex portions formed in a predetermined pattern with an insulator on the surface of the diaphragm facing the fixed electrode with a predetermined gap, the diaphragm can be An extremely good electrostatic transducer that can prevent the vibrating membrane from coming into direct contact with the fixed electrode even if the amplitude is limited and the gap narrowed, thereby effectively improving conversion efficiency. It becomes possible to provide

[Brief explanation of the drawing]

FIG. 1 is a structural explanatory diagram showing one embodiment of an electrostatic transducer according to this invention, and FIG. 2 is a structural explanatory diagram showing another embodiment. 11... Fixed electrode, 12... Spacer, 13... Vibrating membrane (movable electrode), 14...
・・Supporting member, 131゜132・・・・・・(Insulator)
Convex part.

Claims (1)

[Scope of utility model registration request] In an electrostatic transducer in which a fixed electrode and a vibrating membrane (movable electrode) are arranged opposite to each other with a predetermined gap, an insulator is arranged in a predetermined pattern on the vibrating membrane (movable electrode) facing the fixed electrode. An electrostatic transducer characterized by having a formed convex portion.